Sirens wailed as fire trucks, ambulances, paramedics and police rushed to the scene.
Hundreds of orange-clad, helmet-wearing workers were corralled into safe areas under the direction of safety officers.
Firefighters wearing breathing apparatus and carrying heavy-looking rescue equipment rushed into the entrances to Te Waihorotiu Station and disappeared underground.
Onlookers watched nervously from behind safety barriers, and waited.
The drama unfolded over a couple of hours in central Auckland during the second of three exercises to test the co-ordinated response between emergency services and the City Rail Link.
As work moves from heavy construction to the installation, testing and commissioning of lighting, signalling and other systems, the underground emergency response plans are updated and tested to ensure everyone is prepared and able to deal with any issues.
The three new stations for the CRL are undergoing the safety review and emergency drills; Karanga-a-Hape going first yesterday and Maungawhau Station on Tuesday.
So far, so good. , There were no obvious problems, although the work below ground was obscured from view, and yesterday’s exercise wound up at midday as planned.
The researchers aim to create early detection tests, improving survival rates.